I Pretend I'm Okay

Sometimes I wish I didn't, but it has become a habit to pretend to be ok, to lie and say I'm fine.. I'm a really bad liar except when it comes to "how r you?" And "how was school?" I always lie and say I'm fine or it was nice.. or I change the subject without anyone noticing.. reality is I have that constant feeling of not being okay, I kinda feel sad.. I hate school, not cause it's boring or anything, I love my classes, just not the people..
I wish I wasn't feeling sad 90% of the time and I wish people could tell when I'm not okay....